TALLAHASSEE — A state law that requires poor Floridians to pass a drug test before receiving cash welfare assistance — a key tenet of Gov. Rick Scott's campaign — is now being challenged in federal court.

The complaint, from a Navy veteran in Orlando and the American Civil Liberties Union of Florida, acknowledges that the state can drug test in specific instances, such as when there are public safety issues or in cases affecting certain public school children.

But a blanket law ordering tests for all adults who apply for cash help amounts to "unreasonable and suspicionless searches" and violates the Fourth Amendment of the U.S. Constitution, according to the lawsuit.

The suit is the 10th since his inauguration to target either Scott or a policy he supported.

"This is for the benefit of children," Scott said Wednesday about the law. "Welfare is for the benefit of children, and the money should go to the benefit of children. This makes all the sense in the world."

About 51,000 families in Florida receive cash welfare, which averages about $235 per month. That caseload is down 11 percent from September 2010.

Both Scott's office and Rep. Jimmy Smith, a Republican from Inverness who helped write the law, pointed to the 1996 federal law that created Temporary Assistance for Needy Families, the program that provides cash assistance.

The federal law includes a provision that "states shall not be prohibited by the federal government from testing welfare recipients for use of controlled substances nor from sanctioning welfare recipients who test positive for use of controlled substances."

But an ACLU attorney said federal courts have already considered that section of the law.

"Congress can't authorize the states to violate the Constitution," said Maria Kayanan of ACLU of Florida.

A Florida House staff analysis, which lawmakers consulted while crafting the law, pointed out that the proposal "raises important constitutional questions."

The U.S. Supreme Court struck down a Georgia law that aimed to drug test all candidates for political office. But it has not ruled on the constitutionality of drug testing welfare applicants.

In 2000, a federal court in Michigan struck a pilot program that tested all family assistance recipients. That court ruled the program violated the right to privacy under the Fourth Amendment, adding that drug testing was unconstitutional when applied universally or randomly without suspicion of drug use.

Scott pitched the drug testing program to lawmakers and the public as a cost saver for a state.

He said the tests would save the state money because welfare recipients use drugs at a higher rate than the general population.

The costs or savings for the state since the drug testing program started in July were not available on Wednesday.

About 2.5 percent of all applicants have failed the test so far, said Department of Children and Families spokesman Joe Follick.

That compares to 8.7 percent of the general population that uses drugs, according to the 2009 National Survey on Drug Use and Health.

"It's an ugly public policy based on stereotypes and talking points," said Howard Simon, executive director of the ACLU of Florida.

The law could be popular, though. A Quinnipiac University poll in April showed 78 percent of Floridians supported Scott's order to drug test state workers. That order is also being challenged in court.

Smith said there is similar support for testing welfare applicants. "As a blue-collar guy, you would not believe the amount of support from blue-collar people in this state for this law," said Smith, an Army veteran who has worked in pest control, construction and security.

But there's at least one "blue-collar guy" not thrilled about the law. The lead plaintiff in the case is Luis Lebron, a 35-year-old Navy veteran living in Orlando and attending the University of Central Florida. A single father, he cares for his 4-year-old son and disabled mother.

"The new law assumes that everyone who needs a little help has a drug problem," Lebron said Wednesday. "It's wrong and unfair. It judges a whole group of people on their temporary economic situation."

Under the drug testing law, welfare applicants are required to pay for the test but are reimbursed by the state if it is negative.

Positive tests carry an immediate six-month ban on receiving welfare cash. A second positive test results in a three-year ban.

Florida has tried to initiate drug testing before. In 1998, the Legislature approved a pilot project for people receiving temporary cash assistance. The results were lackluster. Of the 8,797 applicants screened for drugs, less than 4 percent tested positive. The project cost the state $2.7 million.

Michael C. Bender can be reached at mbender@sptimes.com or (850) 224-7263. Follow him on Twitter @MichaelCBender.

.FAST FACTS

Florida's welfare drug testing law

. Applicants must pass a drug test to receive benefits.

. State pays for tests of applicants who pass.

. Applicants pay for drug test if they fail; can reapply in six months.